1. Field of the Invention
The present invention relates to a novel apparatus for assisting blood circulation. More particularly, it relates to an apparatus for assisting blood circulation which can circulate blood by inserting an inflow tube and an outflow tube into the body from a peripheral blood vessel with low invasion without thoracotomy to reduce load on the heart.
2. Description of the Prior Art
Auxiliary artificial hearts and full artificial hearts have been widely studied for curing heavy heart diseases and some auxiliary artificial hearts have already been commercialized.
However, application of these technology requires thoracotomy under the full scale and thorough preparation and are practically powerless for saving lives of patients in a sudden emergency like those in acute cardiac insufficiency.
For saving lives of patients in a sudden emergency as described above, assistant blood circulating methods are used for assisting and replacing the pumping function of the heart temporarily with a mechanical method and for recovering the function of the heart.
Counter pulsation method is one of the methods of assistant blood circulating methods, in which blood pressure of aorta is decreased during the systole to decrease the load of the heart and to support the blood flow from the ventricle while it is increased during the diastole to increase the blood flow volume of coronary artery. Thus, this method tries to improve the circulation in the whole body by assisting the function of the malfunctioning ventricle. As the counter pulsation method, the In Aorta Balloon Pumping (IABP) method in which a balloon catheter is inserted into aorta is most generally practiced.
However, the in aorta counter pulsation method has a problem that the effect of the treatment on the whole body is not exhibited much though the load on the heart is reduced and the blood flow volume in the coronary artery is enhanced.
The artery vein bypassing method is used in combination with a membrane oxygen exchange apparatus for the purpose of assisting circulation in the whole body. In the artery vein bypassing method, blood is drawn from an artery and the blood drawn is delivered to a vein by a pump.
These methods all have a problem that the assistance of the circulation in the whole body and the reduction of the load on the heart are not achieved simultaneously.